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8th Jul 12, 18:33 #1
Any keen photographers on here?.. Camera lens mounts question..
Can anyone tell me which specific camera lens mounts (ie K-mount) can you get adapters for to fit to a C mount camera?
Im planning to build a Night vision spotter scope using a 3 stage cascade image intensifier tube from an Israeli tank periscope. It will be quite bulky and heavy but having 3 stages should be equal or at least very close to a Gen 3 scope in performance terms.. at a tiny fraction of the price.
My problem is that Im a bit thick and know very little about lenses/lens mounts. I'd like a decent level of magnification but I know I'll need quite a fast lens to let as much light in as possible.. unless of course I also get myself an IR laser.
I've been advised to use a C-mount on the scope due to it having a set focal distance I've seen a few nice lenses on Ebay that would do the job but not sure which lens mount types I'll be able to get adapters for..
Would it be possible to get a C mount adaptor for something like this?
http://www.ebay.co.uk/itm/CANON-FD-B...-/170834367826Last edited by Zico; 8th Jul 12 at 18:57.
PH
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9th Jul 12, 21:49 #2
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9th Jul 12, 21:53 #3
I hovered over the thread title, got the little pop up thing that has the first few lines of the post and realised that it was out of my depth
The one about the f-ing hairdresser, the space hairdresser & the cowboy. The guy, he's got a tin foil pal & a pedal bin. His father's a robot & he's f-ing f-d his sister. Lego! They're all made of f-ing lego.
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11th Jul 12, 13:04 #4
Yeah, lost me on the first line too.
I recently just use my iPhone camera on holiday instead of taking the proper camera and it worked just as well
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11th Jul 12, 14:50 #5
No. Nothing beats a half-decent DSLR for image clarity, sharpness and view angle.
Although resolution of a phone camera may be comparable (I believe the iPhone 4S has 8MP), the individual pixel size is tiny. For example, a typical sensor size on a DSLR is ~ 20mm x 15mm the iPhone 4s is a mere 4.5mm x 3.4mm.
Similarly, the crop factor on a DSLR is ~1.5 whereas on the iPhone it's 7.6
.
Having said all that, I have no idea what Zico is on about
If everything's under control, you're going too slow. Mario Andretti
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11th Jul 12, 17:08 #6
My iPhone replaced my still & video cemera.
And it does so much more.
I don't leave home with out it.
*advert paid for by satisfied customer.
Sent from my iPhoneWithout sharing there can be no justice,
Without justice there can be no peace,
Without peace there can be no future.
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11th Jul 12, 17:43 #7
Zico,
I'm too out of touch with modern kit to offer any useful advice. But reading your question, I wonder if you are confusing the 'male' and 'female' halves of a lens mount.Duncan Rollo
The more you learn, the more you realise how little you know.
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11th Jul 12, 23:44 #8
I hope not.. but I dont know much about mounts so its very possible!
I'll attempt to clarify.
I had been advised to use a C mount (used by the various old cini cameras) because the focal length (plane) from the lens (at the mount side) to the film (or NV tube in my case) is a known figure, a K, KA, M42 etc adaptor would then be fitted allowing the use of different lens types without me having to re-calculate and cut new shims for the NV tube position (if I upgraded with a lens which required a different mount) in the future.
I've actually since been advised to ignore the C mount + adaptor idea, to just work out the correct distance required for the M42 type mount and I'll still have a wide enough selection of cheap lenses to choose from... and this is what I now plan to do.
I've also found an American forum where quite a few have actually built their own DIY 3 stage cascade spotter scopes using the exact intensifier tube model I actually have. This has given me a lot of ideas (and advice on what not to do).
Some of the results these guys are getting with their homemade scopes in terms of performance is quite remarkable and actually pretty close to the Gen 3 scopes which cost between 3-5k new, not bad when it wont cost me more than 150 to make.. and that figure even includes a 300mw IR laser illuminator with a focusable beam.
See 14th post down on page 8 for single scene pictures/comparisons of the various generations of NV and the Cascade tube DIY NV scope (All pics were starlight, no moon, rural setting) here- DIY Cascade Tube Thread... - Page 8 - AR15.COM
I think I know where Im going with this now but thanks for the replies chaps... and if anyone else on here fancies making themselves one of these drop me a pm and I'll be happy to supply info, ideas and the best places to source the best components at the right prices.
PH
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12th Jul 12, 22:32 #9
I think I understand now.
It used to be possible to get sets of M42 extension tubes (intended for close up photography). If you can get some, it may help to get the focal length right.
Come to think of it, bellows giving variable focus were also around and I think there was even a variable length extendable tube.
Another channel to explore might be bits for an enlarger. If I remember correctly, enlarger lenses use an M38 (Leica) thread.Duncan Rollo
The more you learn, the more you realise how little you know.
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12th Jul 12, 22:46 #10
The one about the f-ing hairdresser, the space hairdresser & the cowboy. The guy, he's got a tin foil pal & a pedal bin. His father's a robot & he's f-ing f-d his sister. Lego! They're all made of f-ing lego.
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13th Jul 12, 00:21 #11
I agree.
For me the case is that "I've been there -done that" in terms of 35mm photography and hi-numbered megapixels.
Right now I've found that I enjoy the simplicity of the iPhone camera and the aid when necessary of the Photoshop or iPhoto programs.
And the video quality is fine with me.
And I think it's cool that you enjoy your toys. It's fun.

Sent from my iPhoneWithout sharing there can be no justice,
Without justice there can be no peace,
Without peace there can be no future.
please click here once a day: http://www.thehungersite.com
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13th Jul 12, 10:05 #12
I think Im going to mount the NV tube inside a slightly larger ally or SS tube and if I cant find out the exact distance required on the net I'll just experiment with spacer rings of different widths until I find the correct focal length for M42 lenses. Mounted inside a tube/pipe it will be much more robust than bellows and avoid the need to add another lens such as an enlarger which would further reduce the amount of light reaching the photocathode.
I'll simply add a potentiometer or rheostat to the NV tube circuit to control brightness/gain there and If I add a IR laser illuminator I wont need fast lenses and may even be able to get good results with zoom/telephoto lenses. I'll also look into building a PWM circuit for the 300mw IR laser to enable me to control its output also.
I've had a lot of interest from local shooters here, so if it works as well as expected it looks like I'll be very busy. I'll try and get some pics of its capabilities up once its complete.
Thanks for the replies.
PH
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13th Jul 12, 20:44 #13
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19th Jul 12, 09:44 #14
I've seen Race's camera, big massive bulky thing, assuming he's using the same one as in 2003
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19th Sep 12, 13:11 #15
I am on the cusp of buying an inexpensive camera with a decent zoom. I pulled this one up.. Sony Cyber-shot DSCHX30V/B Black 18.2 MP 20X Optical Zoom Digital Camera : Digital Cameras - Photo & Video | Dell and it sounds good, although I'm completely out of my depth when it comes to such devices, and would appreciate any guidance. I'm not opposed to paying less
while simultaneously would go a little higher if it makes a substantial difference.
Those who believe in telekinetics raise my hand.
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19th Sep 12, 13:44 #16
I'm also looking around (Christmas is coming) so can I chime in with a couple of other questions?
My problem is that having grown up looking through a camera viewfinder, I can't get used to taking pictures looking at the image on the back of the camera to take pictures - it reminds me of a box Brownie or a Rolleiflex. Is it only DLSRs that have an 'old-fashioned' viewfinder?
Next question: some digitals seem to have a time delay between pressing the button and actually taking the photo - difficult for action photographs of cars. Is this just my imagination?Duncan Rollo
The more you learn, the more you realise how little you know.
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19th Sep 12, 13:53 #17
- Join Date
- Jun 2003
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- 3,599
The time delay isn't part of your imagination. Don't have time to look it up right now but I do think its because there needs to be a switch from projecting the image onto the screen at the back of the camera to taking the actual image. Digital SLRs do not have the same delay.
I got a Canon G11 which is a high end compact with a viewfinder. Bought it to supplement my DSLR but the truth is that it has consigned it to the cupboard attracting dust because the image quality is almost as good and its a whole lot more versatile. I'd recommend its replacement the G12 but there are also a whole load of brand new compact DSLRs arriving for the same price range from various makers. These have a body the size of a compact but with replaceable lenses. I'd take a look at those too to see if you like them.
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19th Sep 12, 16:32 #18
Hey Doc, that Sony does seem to have a decent optical zoom, but at its full 500mm youll likely need a tripod to capture a steady image.
Not sure what the size is on that camera, but as Ive mentioned above, all point n shoot cameras use tiny sensors compared to DSLRs. Im no professional photographer but the best advice I can give is that image quality, in general, is dictated by three parameters:
1. Lens quality
2. Sensor size, and;
3. Resolution.
The choice of lens quality doesnt isnt really a factor in point n shoot cameras as they arent interchangeable so ignore that for now.
What you want to look for in a point n shoot the largest physical sensor size you can find. This allows larger individual pixels which capture the light entering from the lens. The larger the pixel size, the more light they can record on the sensor, the better image quality.
Sometimes sacrificing a high megapixel count for a larger sensor size results in a better picture quality (its not all about MP!).
Because a larger sensor size is able to capture more light, its able to expose the frame better in low light conditions. In DSLRs this allows the use of a faster lens, that is, a faster shutter speed for a given aperture, ideal for action photography (e.g. sports, chasing kids, etc.).
Id suggest taking the time to research cameras, and talking to a salesperson in a decent camera store who can recommend specific equipment to meet your needs. If youre in the U.S. camera stores like Vistek would be a good start. Also, B&H is from where I often order my camera goodies.
Sorry to drone on and Im sure there are others on this forum that could probably provide more elaborate advice
.
If everything's under control, you're going too slow. Mario Andretti
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19th Sep 12, 16:34 #19
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19th Sep 12, 17:31 #20
- Join Date
- Jun 2003
- Posts
- 3,599
Here we are:
Shutter lag - Wikipedia, the free encyclopedia
BTW I second your post above regarding what to look for.



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